[jltait]

Matt sounds like your adapter is for the older style mounts. I will attach a picture. Still might work but you will not be able to use the mount I sent with the crossmember. Personally long term I would try to find the new style adapter, but the mount shown below may work with your current crossmember/adapter combination. You will need (2), (1) sandwiched between the crossmember/adapter at the bolt holes. Not sure this will work 'cause these mounts were used with the old style crossmember before GM commonized them, but it may sit on the crossmember I sent. If it will work the U shape of the mount(s) should straddle the raised hump that runs the length of crossmember.
JLT